The present invention provides towable trailers which provide manoeuvrability and operator safety, and which find particular usefulness in the contracting industries. For example, a construction contractor may be required to move a load of products which are secured on pallets to a jobsite where there is a loading dock onto which the products are to be unloaded. In many such circumstances, the contractor's trailer may not be at the same height as the loading dock, which is typically set at a height suitable for unloading of larger truck trailers. In such situations, it would be necessary to remove the products from trailer using a fork lift on the ground, or the like, and then place the products on the loading dock using the fork lift. In particular, the conventional, prior art, contractor trailer would not be able to be placed at a level where a fork lift could travel directly from the loading dock onto the trailer.
Further, if the products are such that they could be rolled or slid off of the trailer, it would still be necessary to use a fork lift to remove the product from the trailer, and place it on the loading dock.
Moreover, it should be noted that at many locations, access to a fork lift is not always provided, and as a result, it is often necessary to arrange to have a fork lift available for use, in such circumstances. This adds to the cost of delivery of the products.
The present invention, however, provides a towable trailer wherein a platform is provided, with is raisable in a level orientation, so as to be movable into alignment with the loading dock (or other application) level.
Further, many contractor's trailers are provided with ramps at one end, to facilitate the ability of a fork lift to travel onto the trailer, or to roll product off of the trailer onto the ground. However, in many situations, the ramps are commonly angled at a sharp angle so that they will provide the necessary ramp strength. As a result, these ramps commonly have a ramp angle that is too steep for a fork lift, or rollable product, to use. That is, the products or fork lift may be “beached” on the trailer, if the transition between the ramp up and the platform, is too abrupt. The present invention, on the other hand, provides for the platform on the towable trailer to be tiltable, even when the platform is at its lowest position, so that a fork lift truck may be driven onto the platform without difficulty.
Still further, the type of cargo which may be carried on a towable trailer in keeping with the present invention, may be such that its removal from the trailer is best accomplished by dumping the cargo off the rear end of the trailer. For example, a load of crushed stone, sand, or gravel, might fall within this category. Unloading of this type of cargo is also easily accomplished by tilting the platform of the trailer. Indeed, in a combination of effects, it might desirable to unload the cargo onto a raised surface, such as a loading dock. In this situation, the platform of the trailer of the present invention may be raised to the raised surface height, before the platform is tilted to dump the cargo onto the raised surface. As such, raising the platform first, before its cargo can be dumped is easily accomplished using the towable trailer of the present invention.
As a result, contractors and the like may employ the towable trailer of the present invention, to move relatively large or heavy pieces of equipment being installed or removed from a worksite. In many such instances, it is impossible to do so using hauling devices such as vans, pickup trucks or even a flatbed truck. Moreover, the towable trailers of the present invention preclude the need, expense and manoeuvrability, or lack thereof, of larger truck trailers which require fifth wheel tractors to pull them.
In all cases contemplated by the present invention, the requirement for a towed trailer, where the platform of the trailer must be elevated to a required height for removal or loading of its cargo, is met.
In so doing, as will be discussed hereafter, the towable trailer of the present invention employs hydraulic jacks or, in any event, hydraulic cylinders for actuation, or the like, in order to change the elevation and/or tilt of the platform. As is well known to those skilled in the art, the use of hydraulic cylinders provides a very safe environment, especially when the control of the hydraulic cylinders is from a control panel mounted safely on the trailer, or which may even be physically remote from the trailer by perhaps a few meters.
A conventional scissors-style lift assembly is employed in the present invention. However, somewhat unexpectedly, the principal or main hydraulic cylinder which is utilized for elevating and lowering the platform functions by preferably used so as to push its load (the platform, its supporting frame, and a portion of the weight of the scissors-style lift assembly) away from the front end of the towable trailer, rather than pulling it from the back. As a result, the back end of the platform is preferably fixed along a vertical plane.
The present invention is of primary interest in respect of dual axle trailers (or tandem axle trailers), since these trailers typically exhibit adequate stability when standing on their own. However, prior to lifting and/or tilting the platform, the trailer can be stabilized using stabilizing supports, as will be described hereinafter.
Moreover, the trailer itself can be levelled, or set to a desired angle, by the use of these stabilizing supports.
Because of its relatively small size and relative simplicity, a towable trailer in keeping with the present invention may be brought to the market economically, thereby making ownership and usage of the trailer available to small business owners; or even large business owners requiring a considerable number of units of the sort described herein. In any event, especially for a small contractor, the necessity for waiting for pickup and delivery of cargo, and/or the requirement to rent haulage or lifting equipment, may be obviated.
Additionally, the platform can be tilted through use of a second hydraulic cylinder, linked between the scissor jack, and the platform or platform frame, as will be hereinafter described.